Chain stitch sewing machine



Oct. 3, 1933.

Filed Aug. 21, 1931 4 Sheets-Sheet l Oct. 3, 1933. F. LUTZ CHAIN STITCH SEWING MACHINE Filed Aug 21, 1931 4 Sheets-Sheet 2 l ttorncg Oct. 3, 1933.

Filed Aug. 21, 1931 Q w w w w N w S i/lg g x Q T N w k 3% w Q Q :3 Q w R w N R CHINE 4 Sheets-Sheet 3 Gttornegs.

Oct. 3, 1933. F. LU-TZ 1,929,321

CHAIN STITCH SEWING MACHINE Filed Aug. 21, 1931 4 Sheets-Sheet 4 3nnentor Z a Z Gtto megs.

Patented Oct. 3, 1933 t V 1,929,321 V U I CHAIN s'rrrcn SEWING MACHINE Friedrich I naz; Stuttgart, Germany, assignor to Union Special Maschinenfabrik G. n. b.

Stuttgart, Germany Application Aug'ust'ZI, 1931, Serial'No..558,584, Y 1 andin GermanySeptemberS, 1930 Claims. (c1.112-197)' The invention relates to new and useful 1m provements in sewingmachines, andm'oreparticularly to a sewing machine for forming single I chain stitches.

An object of the invention isto provide a machine of the above character h'aving'a' non-thread carrying looper moving into and out of, the needle thread loops to aid in enchaining the needle thread loops; wherein said looperw is so operated, --as to positively place the needle thread loop aboutthe needle, independent of any action of thefeed of the material, sothat the material may be fed in any direction during stitching;

A further object of the invention is to provide a sewing machine of the above type wherein the looperis oscillated for movement into and out of the needle thread loop,'and is given a bodily rotation about the axis of the needle for posi-;

tively placing the needle thread loop carried by the looper around the needle adjacent the point thereof; v Q A further object of the invention is' to provide a machine of the above type with means for, reciprocating the needle and giving a dwell thereto while the'looper is rotated for the placing of the needle thread loop carried .by the looper around theneedle.

'A still further object of the inventio'n'is to provide means for automatically lifting the presser foot so as to permit the manual movement of the fabric in any direction during the stitching operation. r i

In the drawingsj Figure l is a view partly. in front elevation and partly in section showing the machine embodying the improvements; r

Fig.2 is a view partly in plan and. partly in.

horizontal section through the'work arm;

Fig. 3 is a detail in horizontal section at the end of; the work arm and showing the mounting the'looper attherear end of its stroke and the needle at the lower end of its reciprocation;

- which is particularly adapted for-the closing of holes in bags and-the like. The stitch forming directions back and forth and transversely so The looper, whenrin the needle thread loop,- is rotioned' that: the inovementspffthe loope'r"will Fig. 7 is a view showing the looper moved forward to enter the needle thread loop and the, needle "partly retracted. "The looperis also' shown in' broken lines all the way to the forward end of its stroke. H l

Fig. 3 is a view showingtheneedle above the fabric and thelooper' as having been rotated-f bodily through an'arc of 180' degrees; 0'

Fig. 9-is a view'similar to Fig. 8, but showing. the looper as having rotated through an arc of a 360 degrees;

Fig-:10 is aview similar to Fig. 9, omitting the enchained'thread loops and the twist "in thenee- 6 5' dle thread loop, and also: theneedle thread as it passes throughthe needle for the sakeoi cl'ear-. ness, and. witlrthe needle moved downward sothat its 'point'is just below the upper edge of t looper; H J i 'Figxll is'a view similar to Fig; 10, but showing the looper as'having turned'or rotated-in areverse direction from1its first rotation through an arc of 180 degrees;

Fig. 12 is a view similar to Fig. 11; but showing the looper as having rotated in a reverse direction through 360 degrees, and as having returned to its normal position for oscillation, and- Fig. 13 is a view similar to Fig. 12,='but showing the needle as having passed down so thatthe pointis substantially at the lower 'edg'eof the looper. f:

The invention is directed to asewing machine mechanism; includes a needle and a non-thread carrying looperi which cooperates therewith in forming the single thread'chain stitches.

The" material which is being sewed is fed indifferentas to join theneedle threads to the fabric andcompletely close, the hole therethroug'h' byfl-the enchained thread loopsi The machine includes a reciprocating needle anda non-'threadcarrying looper which is mounted foroscillation and also for rotation. The looper is moved into the needle;

thread and holds neeme thread loop so that needle n IleXt descent; willenter" the loop ofneedle thread'carried by the loopr.

tated-so that-*the looper is carried bodily around the longitudinal axis of the needle'. It-is rotated" first in one direction through anarc 'of-360 'de- 'grees, which gives a twistto the needle threadloop, and then it is rotated in the reverse dir'e;--- tion. iDuringthistime-the'nee'dIe 'is so posi wrap the strand of the jneedleiloop-around thei needle. The looper is oscillated by-a rock f lever which inturn is oscillated byarotating cam. 110

through -the forked end of the guide plate 35.

The needle is reciprocated by a needle lever which in turn is actuated by a rotating cam. The looper is rotated by a segment gear which in turn is reciprocated by an actuating lever oscillated by a rotating cam.

The inventionwill be better understood by a detail description of the illustrated embodiment of the invention. The machine includesa standard 1 carrying a work supporting arm 2, which as shown, is of the general cylindrical type. Carried by the standard 1 is an overhanging arm 3 carrying a needle head 4. Mounted for reciprocation in the needle head is a needle bar 5 carrying a needle 6. The needle lever 7 pivoted at 8 is connected by a link 9 to the needle bar for reciprocating the same. This lever 7 carries a roll-' er 10 which runs in a cam. groove formed in a disk 11 carried by the main shaft 12. .This shaft 12 is mounted in suitable bearings in the standard 1.

The fabric to be stitched is supported on the work supporting member or throat plate 13 and is held thereon by a presser foot '14 carried by a presser bar 15. This presser bar is mounted in the needle head and is yieldingly urged against the work support by any suitable means. Mounted on the presser bar is .a collar 16 carrying a forked arm 17 which straddles the needle bar 5. A collar l8carrying a lug to which the link 9 is attached, on the upward movements of the needle bar engages the forked arm 17 and raises the presser foot from the material. [This occurs when the needle is reaching the upper end of its stroke and releases the fabric from the pressure of the presser foot 'so that it may be readily shifted to any desired distanceby the operator, and in any direction. This enables the enchained thread loopsto be laid backand forth'and crosswise until the hole in the fabric is completely filled bythe enchained thread loops. i d

' Cooperating with the needle beneath the work supportisthe looper 19. This looper 19 is in the form of a pointed blade, the under face of which is substantially straight, and the upper face of which is curved, The looper is carried by a shank 20 mounted in a carrier 21 and secured therein by a set screw 22. The carrier 21 is attached to a shaft 23 passing through lugs 24, 24 formed as a part of a support 25. The looper is free to oscillate on this support. 1 Said looper is oscillated by means of a rod 26 which is connected toa lever 27 at 28. The lever 27 is mounted on a cross shaft 29 for free movement thereon, and carries a roll-. er 30 at its upper. end running in a cam groove 31 in-a disk 32-.on the main shaft12 .The rod 26 carries ahead 33 which engages a ball 34 in the shank 20 of the looper. This isfor the purpose of permitting the leoper to rotate in the head. The rod 26 has a threaded engagement with the head '33 andalso with the part connected to the lever 27, and these threads are right and left-hand threads, so that by turning therod, theworking position ofthe looper maybe varied The rod 26 is guided in its endwise movements by a guide plate 35 secured byscrews 86, 36to a vertical web carried by the Work arm 2. Therod passes through an opening in this vertical web and This-preventsany sidewise or lateral movements of. the rod. n v The support 25 for the looper is cone-shaped on its under face and is mounted in a coneshaped bearingin the work arm. A shaft 37 is attached to this support 25 and carries a sleeve having a cone 38 at its lower end mounted in a below the upper edge-of the looper.

at this time comes to a dwell, or substantially to a dwell, and remains-at a dwell while the, looper plate 39 which is attached to the work arm. This sleeve is keyed to the shaft so that when the sleeve is rotated it will. rotate the support 25. The sleeve is provided with a gear 40 which meshes with a gear 41 on a sleeve 42. The sleeve 42 carries a second gear or pinion 43 which meshes with a segment rack 44 carriedby an arm 45 attached to a shaft 46. The shaft 46 is mounted in suitable bearings in the work arm and in the plate 39. This shaft 46 carries an arm 47 which is attached to a rod 48. The rod 48 is in turn attached to a lever 49 mounted freely in the cross shaft 29, and the lever 49 at its upper end carries a roller running in a cam groove in a disk- 50 on thejactuating shaft 12. 'When this segment gear 44 is oscillated, it will impart throughthe gear with which it meshes, and the connecting gears operated thereby, a rotation to the support 25. The cams for reciprocating the looper and for rotating the same, are so timed that the looper moves forward into the needle thread loopto the forward end of its stroke, after which thefllooper is rotated through an arc of 360 degrees, and then it is returned by a reverse rotation through an arc of 360 degrees, after which the looper is retracted from the needle thread loop. The looper moves, alongside of the needle in order to enter the needle thread, loop, and therefore, during its rotation, it ,will' be caused to move bodily around a vertical line con taining the path of reciprocation of the needle. This path of reciprocation 'of the needle is sub-i stantially in alinement with the axis of rotation of the support 25.

Between the plate 39 and the lower member of the work'arm there is,a chamber in whichis placed the segment rack, and the pinions or gears for rotating the looper. This chamber is substantially-closed, and will serve as a lubricating well or chamber for the parts disposed therein.

The operation of the stitch forming mechanism is best illustrated in Figures 6 to 13.. In Figure 6, they needle is at the lowenen'd of its stroke, and has'formed a needle thread loop ihtdwhich ,the looper enters as it'move's forward. At this time, the looper is not being'rota'tedJ InFigure 7, the looper is shown in fulllines'part way into the needle thread loop, and in broken lines all the way into the needle-thread loop. The needle in Figure 7, is shown as moving upward; In Figure 8, the needle hasbeen withdrawn from'th'efabric and is-still on itsup strokep During this time the looper is rotated through 180 degrees; and while it is rotated, it is not moved from its forward position through the oscillating means therefor. The looper continues its rotationuntil it reaches the position shown inFigure 9. The

looper has beenturned throughan arc of 360 degrees. The .needle thread is indicated at n. The needlethread loop on the looper is indicated at n. This rotation of the looper twisted to- 1 gether the strands of the needle threadloop asindicated atn (Fig. 9). In'Figure 10, the twisted strands have been omitted for the sake of clearness. This figure, however, shows the looper in the position as shown in Figuree gbut with the needle-having moved down untilits point is just The needle is being rotated in a reverse direction through an arc of 360 degrees. This; dwell in the movement of the needle is given throughthe shaping When the parts are positioned as shown in Figof the=cam which reciprocates the needle bar,

ure 1o, theneedle, .as-viewedpis infront of -the blade of the looper Thestrand nlof the needle loop is in 'frontof the:blade;iwhile thestrand. n? 1 orlto the position shown inFigure-lhthen the Figure 12. i

into the needle thread'loop which was positively Patent, is- V 1. The combination of a needle, means for re:

bladetof the looper-is moved to the other side,or infront of the needle point, as viewed-.in this figure. .This'movement of the looperip'ositively carried the strand n of the needle-loop partway around the needle at the portion thereof between.

the eye of the needle and the .point of the needle.- The; continued reverse rotation of theilooper to, the position shown in" Figure 12 wilt-positively carry this strand .n ifrom about'theneedle and bring: the blade ofthe looper to the reario'ruoppo site sidelofthe needleafrorn that as viewedrin The strand n of: the needle. thread. loop isanow placed positively across 'the' face of 1 Figure l 1 the :needle-in rear'thereof, while .the strand Jr. has been positively placed acrossthe'face of the: needle in front thereof. In Figure 13, the needle has continu'edits downwardrhovement, while the looperremai'nediatrest in the position shown in The needle has thus passed down laid about the needle by this reverse rotation of the looper. needle thread loop, then thelooper is retracted by its rearward oscillation from the needle thread loop,.and the stitch has been completed.

It will be apparent from the description given above that it is immaterial in which directionthe fabric is fed. The feed of the fabric does not in any way aid in the placing of the needle thread loop for the needle to enter the same. The needle thread loop is placed on the needle by this reverse rotation of the looper. The looper in its rotation, .is the sole active member in positively placing the needle thread loop carried by the looper on the needle. I Having'thusdescribed the invention, what I claim as new and desire to secure by Lettersciprocating the same, a non-thread carrying looper, means for movingthe looper into and out of the needle thread loop, andmeans fonmoving the looper about an axis having a fixed position relative to the path of the needle. and substantially parallel thereto while in the needle thread loop for positively placing the needle thread loop carried thereby on the needle.

2. The combination of a needle, means lating the looper into and out of the needle thread loop, and means for moving the looper about an.

axis having a fixed position relative to the path of the. needle and substantially parallel thereto .while' in the needle thread loop for-positively placing the needle thread loop carried thereby on the needle,

3. The combination of a needle, a non-thread carrying looper cooperating therewith to form:

single thread chain stitches, means for reciprocat' 'ing said needle and for giving a dwell thereto when thepoint of the needle is slightly below the upper edge of the looper, means for oscillating the looper and giving a'jdwell' theretowhile at the forward end of its stroke, and means for ro- After the needle is well into this tion. I I 6. The combination of a work'support, a pressv thread carrying looper cooperating with the. nee- 4 m 1. stroke, and for rotating, saidloop'er ,in' a reverse means; for oscillating: the loopersand giving. a

dwellthereto at the forward .end ofiitsastroke, and means for rotating: said looperbodily about an axis in line with theneedle through an arc of 360 degrees-while the needle is 1 above the material, and for rotatingsaid looper in a reversedi-" rectiongthrough an arczof 1360- degrees for Iposi tivel-y placing the strand-of theneedle thread loop on the looperiagainst thejface' ofztheneedle' between thepoint and the eye thereof; f '5 The combinatiorr'of a work'suppor't, a press-J er foot; apresser' bar .Zcarrying thexpresserfoot,a

needle, aneedle bar carrying'theneedle, anone" threadvc'arrying looper cooperating with the nee'- j dle to form singlethread chainstitches, means for; oscillating saidlooper fortmoving the same into .and out ofpithe needle; thread loops, ,means fixed position relative {to the. path of the needle andsubstantially parallel jthereto while in: the. needle thread loopiorjpositively placing" the strands of the needle thread loop on'the looperv .for moving, the looper about an axishaving a around the needle, and means operated bythe needle bar for lifting the presser foot to permit the free movement of the materialin any. dirt-Sc er foot, a presser bar carrying the presser foot, a needle, a needle bar carrying the needle, anondle to form single thread chain stitches, vmeans for reciprocating the. needle and giving a' dwell 3 thereto when the point of the needle is just below I the upper edge ofthe looper,. means for oscillating the looper and giving a dwell theretoat the forward end of itsstroke, meansfor rotating the looper in'one direction bodily about an axis in 'line with the needle while the needle is on its 'up-stroke, and forirotating said looper-in a reverse direction while the needle is at ,a'dwell for 1 positively placing the needle thread loop .on' the looper about the-needle. V '7. The combination of a thread carrying looper cooperating with the needle to form singlethreadchain stitches, means for reciprocating the needle and giving. a dwell thereto when the point of the needle is just below i for re- *ciprocating the same, a looper, means for, oscilthe looper in one direction'bodilyabout"an axis'in' line with the needle while theneedle ison itsup direction while the'needle is'at a dwell for posi-'- 1 tively placing theyneedlethread 'loop on they I work support, a presser j I footgia presser.bar carrying the presser foot, 9.;

needle, aneedle bar carrying the needle, ,a non- 1251 looper about the needle, andmeans operated by 1 forming single-thread chain stitches, means .for reciprocating. said needle .and for giving a dwelli.

of aineedle, a non-thread V thereto when the point of theneedle is-well below the upper edge of the looper, means for oscillating said looper, and means'ifor rotating. the .looper'when at the. iorward'end of its stroke 1 bodily about anraxisucontaining thevneedle, in-

cludingifissupporti on which said looper is pivotally mounted; a gearfor 'rotating'said'sup'port, an oscillating segmentmeshing' with saidgea'r, and means v for oscillating said: segment. said means for oscillating-the segmentgiving. a dwell to the rotations of the looperl whileithe looperis being. oscillatedinto and outof the needle thread loop. 4 1 V. f 1 9. Thelcombinationrof alneedle,ia noni-thread carrying looper cooperating with said needle for forming single thread chain .stitches;z-means .for'

reciprocating said needle and for givingva dwell thereto when the point or. the needle is well below the upper edgeof the looper, means "forsoscillating said looper,means for rotating-the looper when at the forward end of. itslstroke bodily about an. axis .containingithe needle, including a support on which said looper is' pivotally mounted, agear for rotating 'saidsupport, an oscillating segment meshing with said gear, means for oscillating said segment, said means for oscillating the segment giving a dwell to the rotation of the looper while the looper 'is being oscillated into and out of the needle thread loop, said means for I oscillating the looper-including ball on vthe shank'of the looper, and a rod having aheadengaging the ball whereby the looper may, be osciltheirod; I

lated and'isfreefto'rotate in itsconnection to V 10. Theco bination of a needle, anonthread carrying looper cooperating with said needlefor forming single: thread chain stitches, means for reciprocating said needle and for giving'a dwell thereto-whenthe point of the needle is well below theupper edge: of the looper, means for oscillatding said "looper, means for rotating the looper when at the forward end of its stroke bodily about an axis. containing-the needle, including a support'on which said looper is pivotally mounted, v 

